Oil burner head



July 15, 1952 w. P. PoHLE 2,603,279

OIL BURNER HEAD Filed Sept. 8, 1948 2 SHEETS-SHEET l if ZZ W. P. POHLE OIL BURNER HEAD July l5, 1952 2V SHEETS-SHEET 2 Filed Sept. 8, 1948 Patented July 15, 1952 agrary orifice on. BURNER HEAD Werner fP. Pohle, Lynn, Mass., assigner `to Lynn Mass., a corporation ofv Products Co., Lynn,

Massachusetts.

Application September 8, 1948, Serial No. 48,181

1 Claim.

'Ihis invention relates to improvements in oil burner heads by means of which a stream f oil spray and air mixture is projected into a fireboX for combustion. In heating plants for homes and equivalent structures, 'wherein oil is used as the fuel, various types of burners are employed, each being designed for the purpose of promoting complete combustion of the oil so that the maximum amount of heat will be realized from the fuel burned, and smoke and soot will be avoided. For domestic use, quiet operationis also a desirable feature to be sought in designing a burner;

One type of burner which has heretofore been generally successful in burning petroleum oil distillates derived by the old straight run or thermal process of distillation, has comprised an outer tubular housing with a short frusto-conical flange at the. delivery end, an inner housing within and coaxial with the outer housing, helical vanes in the space between the housings to impart a whirling motion to the air stream iiowing through such space, and an atomizing nozzle for fuel within the inner housing and at or near the delivery end thereof. In operation, the projecting of the oil spray from the fuel nozzle has an .aspirating effect tending to reduce the pressure of the air within the inner housing and thus to suck the flame to some extent back into the housing. To avoid such reduction of pres# sure Within the inner housing, air is admitted into the inner housing from the main stream owing through theouter housing toward the delivery end thereof. By making simple empirical adjustments in apparatus of this description, the thermal run distillates can usually be burned without an excessive amount of carbon soot formation.

Since the development of catalytic processes for the refinement of fuel oils, the catalytic renedoils have been produced on a constantly increasing scale with the result that most fuel oils for `domestic use contain at least catalytic refined oil and the present trend is toward a higher percentage toward an ultimate probable 100% of catalytic refined oil.

Catalytic refined oils are more diiiicult to burn cleanly and efficiently than straight run distillates, and the increasing production and use of the former has stimulated the quest for improved combustion apparatus. In the embodiment of the invention hereinafter described, a primary air stream is blown through the annular passage between the outer and inner housings and is discharged from the outer housing with a whirl- 2 ing movement imparted by vanes in theY passage; A secondary stream of air is admitted to the inner housing and is discharged therefrom with a whirling movement. By whirling the secondary airstream, a comparatively Wide range of rate of fuel consumption can be had without adjustment of the quantity rate of air now in the secondary stream such as is necessary when there is no whirling motion in the second-I ary stream. A frusto-conical iiange or nozzle at the delivery end of the outer housing co-` operates with they vanes in themain air passageto causethe main air stream to issue from the delivery orifice in the form of va hollow cone. The inner housing terminates in a similar but smaller frusto-conical flange ornozzle, the ele'- ments of which are parallel to the corresponding elements of the outer nozzle. Helical air passages within the inner housing are arranged to cause the secondary stream of air to discharge from the inner housing in the form of a hollow cone. It is desirable that the helix angles of the air streams be such that they will issue from the nozzles with substantially equal conical angles.

' The fuel nozzle emits atomized oil in a conical spray. By constructing and adjusting the air and fuel nozzles so that the conical streams of air and atomized oil have substantially the same apex angle, efficient combustion of the Yfuel with a quiet, steady flame is obtained.

For a more complete understanding of the invention, reference may be had to the following description thereof and to the drawings, of whichf Figure l is aside elevation mechanism; Y

Figure 2 is a side elevation of the burner head shown in Figure 1,a portion being broken away to show inner parts; y

Figure 3 is a perspective view of some of the' inner parts, shown separately; and

Figure 4 is a section on the line @1 -1ll ofFig-Y ure 2. A burner of the kind for which the head embodying the present invention is especially designed is illustrated in Figure l. It includes a base IIJ on which is supported a main housing I2 containing the usual components of a burner such as a blower, a fuel pump and a motor. From the main housing, the burner head I4 projects horizontally. The burner head comprises an outer cylindrical housing I6 having at its discharge end a frusto-conical nozzle plate I8 which can conveniently be a detachable eleof an oil burner ment held in place by studs 28 which engage in bayonet slots in the nozzle plate I8.

Within the tubular housing I6 and coaxial therewith, is an inner, cylindrical housing 22 which has a frusto-conical nozzle plate 24 at its discharge end. The two nozzle plates I8 and 24 form reduced orifices for the two housings and preferably have substantially the same degree of convergence. In other words, the apex angles of the cones of the nozzle plates are substantially equal. The apex angles of the plates I8 and 24 illustrated on the drawings are 80. but the invention is not limited to this particular angle. Since the two housings I6 and 22 are coaxial, they define between them an annular space 26 which serves as the passage or duct through which the main air stream flows to the orifice of the outer housing. In the burner head shown, the diameter of the inner housing is approximately fourfths that of the outer housing, that is, considerably more than half. Thus, the annular passage 26 is somewhat narrow, its width being only about one-tenth of the diameter of the outer housing. The width of the annular passage 26 is understood to mean the radial distance between the inner and outer housings at any point. The main stream of air which flows through the burner head is thus in the form of a somewhat thin cylindrical shell as it approaches the orifice of the outer housing. This stream is given a whirling motion by a series of helical vanes 38 which are located in the passage 26 and may conveniently be secured to the outer surface of the inner housing 22, as shown, these vanes dividing the passage 26 into a series of passages, six being indicated in Figure 4.

Fitted within the inner housing 22 and spaced from the orice thereof is a transverse barrier member or wall. As shown, this barrier member is made up of a body 32 of porcelain or other suitable insulating material, and two annular rings 34 and 36 adapted to fit on and be secured to a cylindrical mid-portion 38 of the body 32 by screws 39 or other suitable means. The body 32 carries the customary electrodes 40 which are used to ignite the fuel sprayed from the fuel nozzle, as hereinafter described. The fuel pipe 42, which carries fuel to the burner head, extends through the center of the body 32 and terminates in an atomizing nozzle 44 in the orifice of the f inner housing 22. The housing 22 is preferably secured to the barrier member by radial screws 45 which extend through the shell of the housing into the ring 34.

In order to break the vacuum or lowered pressure within the inner housing which would otherwise result from the aspirating effect of the conical fuel spray ejected from the nozzle 44 through the orifice of the inner housing, air is admitted to the inner housing through the barrier member.

For this purpose, the rings 34 and 36 are grooved, as at 46 and 48, in their peripheral surfaces. These grooves, together with the adjacent portions of the inner housing, form a series of spaced passages for a secondary air flow within the inner housing. When the rings 34 and 36 are assembled on the body 32, each of the grooves 46 communicates with a groove 48 to form an air passage adjacent to the inner surface of the inner housing 22. The cross sectional area of the primary air passage 26 is several times larger than the combined cross sectional areas of the secondary passages formed by the grooves 46, the ratio of such areas as shown in Figure 4 being approximately twelve to one. The grooves 46, for convenience of manufacture, may be parallel to the axis of the burner head, but the grooves 48, from which the secondary air streams are discharged into forward portion of the inner housing which contains the fuel nozzle 44, are helical so as to cause the air streams against the inside of the inner housing to advance to and through the orifice with a whirling motion. As shown, the vanes 30 and grooves 48 are arranged so that the primary and secondary air streams whirl in the same direction as they emerge from the orifices of the housings. The nozzle plates I8 and 24 guide the whirling streams so that they issue in cones of substantially equal angles of divergence. As a result, combustion of the fuel is quiet, complete and efficient, even in the case of catalytically cracked fuels.

The inner housing and the fuel nozzle are each axially adjustable with respect to the outer housing to cause the two air cones and the fuel cone to blend most advantageously. When the desired adjustment has been made in a given installation, it will ordinarily not be necessary to make any further adjustment unless a change is made to a different fuel.

I claim:

A burner head for liquid fuel comprising means for emitting two substantially coinciding conical streams of air, said means including two coaxial cylindrical tubes with walls uniformly spaced apart to form an annular passage having a width which is small in comparison with the diameters of the tubes, helical vanes in said passage, frustoconical nozzles on the discharge ends of said tubes, a transverse wall across the rear end of the inner tube with a series of spaced helical passages therethrough arranged to direct jets of air in helical Apaths along the interior surface of the inner tube, the combined cross-sectional area of said spaced helical passages being small in comparison with the cross sectional area of said annular passage and means for projecting from the discharge end of said burner head a conical spray of fuel substantially coinciding with said conical air streams.

WERNER P. POHLE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,777,141 Howden Sept. 30,- 1930 2,066,806 Smith Jan. 5,- 1937 2,120,387 Bargeboer June 14, 1938 2,221,519 Jones et al. Nov. 12, 1940 2,393,897 Glendenning Jan. 29, 1946 2,451,964 Logan' oct. 19. 194s 2,531,538 Smith Nov. 2-8, 1950 2,553,130 Cadella May 1,5, 1951 FOREIGN PATENTS Number Country Date 340,858 Great Britain Jan. 8, 1931 

